109.41.00

- Remove all uses of "unwrapped" pointers

  Unwrapped pointers cannot coexist with the remove-page-table
  optimization.

  Removed all the C stubs for reading/writing and used instead either
  the new primitives of the next OCaml or standard OCaml code
  reading/writing integers byte by byte.

  Since we don't have unsafe/safe functions anymore but only safe ones,
  removed all the `bin_{read,write}_t_` functions.

  Also renamed `bin_read_t__` to `__bin_read_t__` for the same reason as
  sexplib: to avoid confusion with the function generated for `t_` and
  hide it in the toplevel.